Hibernate - SUNY Oneonta

Transcript Hibernate - SUNY Oneonta

Hibernate
Hibernate
• Hibernate is a powerful, high performance
object/relational persistence and query service.
Hibernate lets you develop persistent classes following
object-oriented idiom - including association, inheritance,
polymorphism, composition, and collections. Hibernate
allows you to express queries in its own portable SQL
extension (HQL), as well as in native SQL, or with an
object-oriented Criteria and Example API.
• Unlike many other persistence solutions, Hibernate does
not hide the power of SQL from you and guarantees that
your investment in relational technology and knowledge
is as valid as always. The LGPL open source license
allows the use of Hibernate and NHibernate in open
source and commercial projects.
Java Persistence with Hibernate
• The Java Persistence API is the standard object/relational mapping
and persistence management interface of the Java EE 5.0 platform.
As part of the EJB 3.0 specification effort, it is supported by all major
vendors of the Java industry.
• Hibernate implements the Java Persistence object/relational
mapping and persistence management interfaces with the Hibernate
Annotations and Hibernate EntityManager modules, on top of the
mature and powerful Hibernate Core.
• The Hibernate modules can be stacked and combined as desired.
You can use the Hibernate Java Persistence provider in any
environment, Java SE 5.0 or Java EE 5.0. The Hibernate Java
Persistence provider is fully certified and passes the Sun TCK.
Hibernate Annotations
• Project Lead: Emmanuel BernardLatest release: 3.4.0 GA
(Changelog) (Road Map)Release date: 20.08.2008Requirements:
Hibernate Core 3.3.x, JDK 5.0Hibernate, like all other
object/relational mapping tools, requires metadata that governs the
transformation of data from one representation to the other (and vice
versa). As an option, you can now use JDK 5.0 annotations for
object/relational mapping with Hibernate 3.2. You can use
annotations in addition to or as a replacement of XML mapping
metadata.
• The Hibernate Annotations package includes:
• Standardized Java Persistence and EJB 3.0 (JSR 220)
object/relational mapping annotations
• Hibernate-specific extension annotations for performance
optimization and special mappings
• You can use Hibernate extension annotations on top of standardized
Java Persistence annotations to utilize all native Hibernate features.
More jar file downloads
• You will need persistence and ejb jar files: ejb,
persistence, jndi, geronimo-ejb, ejb3-persistence
and javaee.
• Many Hibernate tutorials out there:
• http://www.hibernate.org/hib_docs/reference/en/
html/tutorial.html
• http://www.roseindia.net/hibernate/index.shtml
• http://www.hibernate.org/hib_docs/reference/en/
html/tutorial-webapp.html
• http://www.inf.ed.ac.uk/teaching/courses/ec/han
douts/quickstart.pdf
Hibernate tutorials
• Various modified/new tutorials appear here. I
used mysql, but that is not a requirement.
• Hibernate standardizes the db interface. A config
file specifies the actual db service and the
dialect to use, and other config files, called hbm,
map the individual tables. Instead of providerspecific connection and query details, the
program uses the hibernate “interface” to
interact with the database.
A hibernate app (not a web app!)
Will consist of
• one or more classes (POJOs) to be populated
from/copied to database tables.
• A mapping file for each named
classname.hbm.xml mapping each to the
database table it corresponds to
• Configuration files as needed for log4j and
hibernate… especially hibernate.cfg.xml
• A controller class
• And so on…
First hibernate tutorial
• Using hibernate with a mysql database
and a few simple java classes.
• Link for tutorial:
http://www.hibernate.org/hib_docs/referen
ce/en/html/tutorial-firstapp.html
• This tutorial has many omissions, most
notably library jar files needed. I also had
to modify some classes (HibernateUtil).
• It does come with an ant build
Directory structure
• Appdir
– bin
– src
•
•
•
•
•
log4j.properties
hibernate.cfg.xml
Event.hbm.xml
hibernate.properties --- not included in this example
events(dir)
– Event.java
• util(dir)
– EventManager.java
– HibernateUtil.java
– lib
Notes about lib
•
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•
•
•
•
•
•
You’ll need
Hibernate
Cp30
Antlr
Jta
Dom4j
Commons logging
Just 2 files from slf4j…note screen shot
My lib directory
build.xml
<project name="hibernate-tutorial" default="compile">
<property name="sourcedir" value="${basedir}/src"/>
<property name="targetdir" value="${basedir}/bin"/>
<property name="librarydir" value="${basedir}/lib"/>
<path id="libraries">
<fileset dir="${librarydir}">
<include name="*.jar"/>
</fileset>
</path>
<target name="clean">
<delete dir="${targetdir}"/>
<mkdir dir="${targetdir}"/>
</target>
<target name="compile" depends="clean, copy-resources">
<javac srcdir="${sourcedir}"
destdir="${targetdir}"
classpathref="libraries"/>
</target>
<target name="copy-resources">
<copy todir="${targetdir}">
<fileset dir="${sourcedir}">
<exclude name="**/*.java"/>
</fileset>
</copy>
</target>
<target name="run" depends="compile">
<java fork="true" classname="events.EventManager" classpathref="libraries">
<classpath path="${targetdir}"/>
<arg value="${action}"/>
</java>
</target>
</project>
HibernateUtil.java
• This class gets the hibernate session
factory or throws an exception
• With minor variations it appears in many
hibernate applications
HibernateUtil.java
package util;
import org.hibernate.*;
import org.hibernate.cfg.*;
public class HibernateUtil {
private static final SessionFactory sessionFactory;
static {
try {
System.out.println("in try for build session factory");
// Create the SessionFactory from hibernate.cfg.xml
sessionFactory = new Configuration().configure().buildSessionFactory();
System.out.println("back from build session factory");
} catch (Throwable ex) {
// Make sure you log the exception, as it might be swallowed
System.err.println("Initial SessionFactory creation failed." + ex);
System.out.println("Initial SessionFactory creation failed." + ex);
throw new ExceptionInInitializerError(ex);
}
}
public static SessionFactory getSessionFactory() {
return sessionFactory;
}
}
EventManager.java (also in slide notes)… a controller class for
handling “events”
package events;
import org.hibernate.*;
import org.hibernate.cfg.*;
import java.util.Date;
import java.util.*;
import util.HibernateUtil;
public class EventManager {
public static void main(String[] args) {//main
EventManager mgr = new EventManager();
System.out.println("Event Manager before if") ;
/////I stuck in all these println
if (args[0].equals("store")) {//if------A store command
System.out.println("create and store");
mgr.createAndStoreEvent("My Event", new Date());
}//if
else if (args[0].equals("list")) {//------A list command
System.out.println("list events");
List events = mgr.listEvents();
for (int i = 0; i < events.size(); i++) {
Event theEvent = (Event) events.get(i);
System.out.println("Event: " + theEvent.getTitle() +
" Time: " + theEvent.getDate());
}
}System.out.println("Event Manager: completed if");
HibernateUtil.getSessionFactory().close();
}
EventManager.java continued
private List listEvents() {
System.out.println("Event Manager... in list events method");
SessionFactory sessionFactory = HibernateUtil.getSessionFactory();
Session session =sessionFactory.openSession();
session.beginTransaction();
List result = session.createQuery("from Event").list();
session.getTransaction().commit();
return result;
}
private void createAndStoreEvent(String title, Date theDate) {
System.out.println("Event Manager... create and store method");
SessionFactory sessionFactory = HibernateUtil.getSessionFactory();
Session session =sessionFactory.openSession();
System.out.println(".. before begin transaction");
session.beginTransaction();
System.out.println(".. transaction started");
Event theEvent = new Event();
theEvent.setTitle(title);
theEvent.setDate(theDate);
session.save(theEvent);
System.out.println("session save completed");
session.getTransaction().commit();
System.out.println("after commit in create and save");
}
}
Event.java
package events;
import java.util.Date;
public class Event {
private Long id;
private String title;
private Date date;
//Eclipse or Netbeans will build the rest… default constructor and getter/setters
public Event() {}
public Long getId() {
return id;
}
private void setId(Long id) {
this.id = id;
}
public Date getDate() {
return date;
}
public void setDate(Date date) {
this.date = date;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
}
Event.hbm.xml --such a file (and the
corresponding java class) is needed for each table
mapped…note how primary key autoincrement
primary key appears
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="events.Event" table="EVENTS">
<id name="id" column="EVENT_ID">
<generator class="native"/>
</id>
<property name="date" type="timestamp" column="EVENT_DATE"/>
<property name="title"/>
</class>
</hibernate-mapping>
hibernate.cfg.xml contains connection info, db
name, user name & pw and other information
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>

<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql://localhost/mydb</property>
<property name="connection.username">root</property>
<property name="connection.password"></property>

<property name="hibernate.connection.pool_size">10</property>

<property name="dialect">org.hibernate.dialect.MySQLDialect</property>

<property name="show_sql">true</property>
<property name="hbm2ddl.auto">update</property>
<mapping resource="Event.hbm.xml"/>
</session-factory>
</hibernate-configuration>
Log4j.properties
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p
%c{1}:%L - %m%n
log4j.rootLogger=info, stdout
log4j.logger.org.hibernate.test=info
log4j.logger.org.hibernate.tool.hbm2ddl=debug
remark
• You’ll need to create a mysql database
and table for this example and you need to
start the database server before running
the example.
• Run the example in the root directory on
the commandline either with
ant run –Daction=store
• Or
ant run –Daction=list
First tutorial…output for store
C:\hibernateexample>ant run -Daction=store
Buildfile: build.xml
clean:
[delete] Deleting directory C:\hibernateexample\bin
[mkdir] Created dir: C:\hibernateexample\bin
copy-resources:
[copy] Copying 6 files to C:\hibernateexample\bin
[copy] Copied 2 empty directories to 1 empty directory under C:\hibernateex
ample\bin
compile:
[javac] Compiling 3 source files to C:\hibernateexample\bin
run:
[java] Event Manager before if
[java] create and store
[java] Event Manager... create and store method
[java] in try for build session factory
<<<omitted a lot…see slide notes>>>
[java] 719 [main] INFO org.hibernate.tool.hbm2ddl.SchemaUpdate - schema upd
ate complete
[java] back from build session factory
[java] .. before begin transaction
[java] .. transaction started
[java] Hibernate: insert into EVENTS (EVENT_DATE, title) values (?, ?)
[java] session save completed
[java] after commit in create and save
[java] 907 [main] INFO org.hibernate.impl.SessionFactoryImpl - closing
[java] 907 [main] INFO org.hibernate.connection.DriverManagerConnectionProv
ider - cleaning up connection pool: jdbc:mysql://localhost/mydb
[java] Event Manager: completed if
BUILD SUCCESSFUL
Total time: 2 seconds
C:\hibernateexample>
Run –list …entirety in notes
C:\hibernateexample>ant run -Daction=list
Buildfile: build.xml
clean:
…
copy-resources:
…
compile:
[javac] Compiling 3 source files to C:\hibernateexample\bin
run:
<<left out a lot of output here>>>>
[java] 531 [main] INFO org.hibernate.impl.SessionFactoryImpl - building ses
sion factory
[java] 719 [main] INFO org.hibernate.impl.SessionFactoryObjectFactory - Not
binding factory to JNDI, no JNDI name configured
…
[title, event_date, event_id]
[java] 734 [main] INFO org.hibernate.tool.hbm2ddl.TableMetadata - foreign k
eys: []
[java] 734 [main] INFO org.hibernate.tool.hbm2ddl.TableMetadata - indexes:
[event_id]
[java] 734 [main] INFO org.hibernate.tool.hbm2ddl.SchemaUpdate - schema upd
ate complete
[java] back from build session factory
[java] Hibernate: select event0_.EVENT_ID as EVENT1_0_, event0_.EVENT_DATE
as EVENT2_0_, event0_.title as title0_ from EVENTS event0_
[java] Event: My Event Time: 2009-03-03 00:00:00.0
[java] 1062 [main] INFO org.hibernate.impl.SessionFactoryImpl - closing
[java] Event Manager: completed if
[java] 1062 [main] INFO org.hibernate.connection.DriverManagerConnectionPro
vider - cleaning up connection pool: jdbc:mysql://localhost/mydb
BUILD SUCCESSFUL
Total time: 2 seconds
C:\hibernateexample>
Redo with a GUI…needs some
improvement
notes
• First, of course, get the tutorial working.
• Modify the EventManager so it opens a JFrame
with two button, list and store.
• Should have another button to delete * from
db/table)
• Display stored events in a textarea.
• Enter data for the event in a textfield.
• The tutorial code uses a timestamp, but maybe
something else like a string with MM/DD/YY
format would be nicer.
So what’s the point of hibernate?
• A uniform connection (the session thingy)
and sql dialect in your object. This doesn’t
change as you port your application.
• The hibernate.cfg.xml (NOT your java
code) gets modified if you port or change
database servers.
The hibernate webapp
• Recall a webapp consists of a servlet
(class) sitting in a fixed directory structure,
with a web.xml configuration file.
• A webapp requires a container (Tomcat,
Jetty, JBoss,…) to run it.
• A server would typically include a (servlet)
container.
Tomcat Web App Directory Structure
Your servlet container
Dir named Webapps
Dir named ROOT
Other web app directories…
A webapp dir
Servlets- put html in here
WEB-INF
web.xml
Classes dir- put the packages/ .class files here
WEB-INF\web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4"
xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<servlet>
<servlet-name>Event Manager</servlet-name>
<servlet-class>events.EventManagerServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>Event Manager</servlet-name>
<url-pattern>/eventmanager</url-pattern>
</servlet-mapping>
</web-app>
Where do files go? Shown in
another slide but note…
• Hibernate.cfg goes in classes dir
• Event.hbm.xml goes into Events dir (I
think) …if not, then into classes dir
The 1-table hibernate web app
•
http://www.hibernate.org/hib_docs/reference/e
n/html/tutorial-webapp.html
• This tutorial came from hibernate.org. I think it is
basically correct, although I made changes to
the servlet trying to fix unrelated problems. I also
used my own HibernateUtil class (shown in
previous tutorial).
• Not very many details about the directory
structure were given in the tutorial, but I give
them here.
Servlet running in tomcat
Servlet entirety in slide notes
package events;
import java.io.*;
import java.net.*;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import javax.servlet.*;
import javax.servlet.http.*;
import util.HibernateUtil;
import org.hibernate.*;
public class EventManagerServlet extends HttpServlet {
SessionFactory sessionFactory;
Session session;
Servlet continued
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
SimpleDateFormat dateFormatter = new SimpleDateFormat("dd.MM.yyyy");
PrintWriter out = response.getWriter();
out.println("<html><head><title>Event Manager</title></head><body>");
try {
sessionFactory = HibernateUtil.getSessionFactory();
session =sessionFactory.openSession();
session.beginTransaction();
if ("store".equals(request.getParameter("action"))) {
String eventTitle = request.getParameter("eventTitle");
String eventDate = request.getParameter("eventDate");
if ("".equals(eventTitle) || "".equals(eventDate)) {
out.println("<b><i>Please enter event title and date.</i></b>");
} else {
System.out.println("before call to create and store");
createAndStoreEvent(eventTitle, dateFormatter.parse(eventDate));
out.println("<b><i>Added event.</i></b>");
}
}
printEventForm(out);
listEvents(out, dateFormatter);
// End unit of work
//HibernateUtil.getSessionFactory().getCurrentSession().getTransaction().commit();
session.getTransaction().commit();
System.out.println("commit after save");
} catch (Exception ex) {
HibernateUtil.getSessionFactory().getCurrentSession().getTransaction().rollback();
throw new ServletException(ex);
} }
Servlet continued
private void printEventForm(PrintWriter out) {
out.println("<h2>Add new event:</h2>");
out.println("<form>");
out.println("Title: <input name='eventTitle' length='50'/><br/>");
out.println("Date (e.g. 24.12.2009): <input name='eventDate' length='10'/><br/>");
out.println("<input type='submit' name='action' value='store'/>");
out.println("</form>");
}
private void listEvents(PrintWriter out, SimpleDateFormat dateFormatter) {
List result = HibernateUtil.getSessionFactory().getCurrentSession().createCriteria(Event.class).list();
if (result.size() > 0) {
out.println("<h2>Events in database:</h2>");
out.println("<table border='1'>");
out.println("<tr>");
out.println("<th>Event title</th>");
out.println("<th>Event date</th>");
out.println("</tr>");
for (Iterator it = result.iterator(); it.hasNext();) {
Event event = (Event) it.next();
out.println("<tr>");
out.println("<td>" + event.getTitle() + "</td>");
out.println("<td>" + dateFormatter.format(event.getDate()) + "</td>");
out.println("</tr>");
}
out.println("</table>");
}
}
Servlet continued
protected void createAndStoreEvent(String title, Date theDate) {
Event theEvent = new Event();
theEvent.setTitle(title);
theEvent.setDate(theDate);
HibernateUtil.getSessionFactory().getCurrentSession().save(theEvent);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
}
Boldfaced line added to cfg
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>

<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql://localhost/mydb</property>
<property name="connection.username">root</property>
<property name="connection.password"></property>

<property name="hibernate.connection.pool_size">10</property>

<property name="dialect">org.hibernate.dialect.MySQLDialect</property>

<property name="show_sql">true</property>
<property name="hbm2ddl.auto">update</property>
<property name="current_session_context_class">thread</property>
<mapping resource="Event.hbm.xml"/>
</session-factory>
</hibernate-configuration>
build.xml (an app located at c:\myapp would have
a war called C:\myapp.war)
<project name="hibernate-tutorial" default="compile">
<property name="sourcedir" value="${basedir}/src"/>
<property name="targetdir" value="${basedir}/bin"/>
<property name="librarydir" value="${basedir}/lib"/>
<path id="libraries">
<fileset dir="${librarydir}">
<include name="*.jar"/>
</fileset>
</path>
<target name="clean">
<delete dir="${targetdir}"/>
<mkdir dir="${targetdir}"/>
</target>
<target name="compile" depends="clean, copy-resources">
<javac srcdir="${sourcedir}"
destdir="${targetdir}"
classpathref="libraries"/>
</target>
<target name="copy-resources">
<copy todir="${targetdir}">
<fileset dir="${sourcedir}">
<exclude name="**/*.java"/>
</fileset>
</copy>
</target>
Build.xml continued
<target name="run" depends="compile">
<java fork="true" classname="events.EventManager2"
classpathref="libraries">
<classpath path="${targetdir}"/>
<arg value="${action}"/>
</java>
</target>
<target name="war" depends="compile">
<war destfile="hibernate-tutorial.war" webxml="web.xml">
<lib dir="${librarydir}">
<exclude name="jsdk*.jar"/>
</lib>
<classes dir="${targetdir}"/>
</war>
</target>
</project>
Package things in WEB-INF as
shown here
• WEB-INF
– classes (dir)
• events(dir)
– Event.class (no changes to this file)
– EventManagerServlet.class
– Event.hbm.xml (no changes to this file)
• util(dir)
– HibernateUtil.class (this file same as in previous project)
• Hibernate.cfg.xml
– lib(dir) (no changes to this)
– log4j.properties(no changes to this)
– web.xml (shown above)
Jar
I used jar instead of ant build:
jar –cvf appname.war WEB-INF
This creates a jar called appname.war with a dir in it named
WEB-INF and all WEB-INF’s contents.
General syntax of jar is
jar –switch name-of.war list_of_files list_of_dirs
You’ll need to move files and directories as per web app
structure before creating a war file.
What’s next?
• CRUD against a database using one or
more servlets, like your servlet database
project, except use a hibernate interface.
Two examples: multiple tables & crud
• documentation
http://www.hibernate.org/hib_docs/referen
ce/en/html/
Adding to tables & listing
• I modified a previous example, adding a
people table and displaying contents of
two tables.
• I did not do a select, I just printed the
event title in the same position. But since
the numbers are allocated sequentially, I
could have used select title from Event
where id=number
My tables
• My People table and my Event table both have ids as
primary key, auto-incremented.
• In the hbm, these are identified as
<id name=“some_field" column=“table_col">
<generator class="native"/>
</id>
Dir structure
• WEB-INF
–
–
–
–
log4j.properties
web.xml
lib (contents shown later)
classes
• hibernate.cfg.xml
• util
– Same HibernateUtil.java as previous
• events
–
–
–
–
–
Same Event.java as previous
People.java
EventManagerServlet.java
People.hbm.xml
Event.hbm.xml (unchanged from prev example)
some of these may be unnecessary
but I whittled it down some
Entire Servlet in notes
package events;
import java.io.*;
import java.net.*;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import javax.servlet.*;
import javax.servlet.http.*;
import util.HibernateUtil;
import org.hibernate.*;
public class EventManagerServlet extends HttpServlet {
SessionFactory sessionFactory;
List result1,result2;
Session session;
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
SimpleDateFormat dateFormatter = new SimpleDateFormat("dd.MM.yyyy");
PrintWriter out = response.getWriter();
out.println("<html><head><title>Event Manager</title></head><body>");
try {
// Begin unit of work
// HibernateUtil.getSessionFactory().getCurrentSession().beginTransaction();
sessionFactory = HibernateUtil.getSessionFactory();
session =sessionFactory.openSession();
session.beginTransaction();
Servlet…print form, get session
// Handle actions
if ("store".equals(request.getParameter("action"))) {
String eventTitle = request.getParameter("eventTitle");
String eventDate = request.getParameter("eventDate");
String name = request.getParameter("name");
String phone = request.getParameter("phone");
if ("".equals(eventTitle) || "".equals(eventDate)||name.equals("")||phone.equals("")) {
out.println("<b><i>Please enter person, event title and date.</i></b>");
} else {
System.out.println("before call to create and store");
createAndStoreEvent(name, phone,eventTitle, dateFormatter.parse(eventDate));
out.println("<b><i>Added event.</i></b>");
}
}
// Print page
printEventForm(out);
System.out.println("back in process ...about to call listevents");
listEvents(out, dateFormatter);
// End unit of work
//HibernateUtil.getSessionFactory().getCurrentSession().getTransaction().commit();
session.getTransaction().commit();
System.out.println("commit after save");
} catch (Exception ex) {
System.out.println(ex.toString());
HibernateUtil.getSessionFactory().getCurrentSession().getTransaction().rollback();
throw new ServletException(ex);
}
}
Servlet: the form and table of events
private void printEventForm(PrintWriter out) {
out.println("<h2>Add new event:</h2>");
out.println("<form>");
out.println("Title: <input name='eventTitle' length='50'/><br/>");
out.println("Date (e.g. 24.12.2009): <input name='eventDate' length='10'/><br/>");
out.println("Contact person: <input name='name' length='50'/><br/>");
out.println("Phone(e.g. (123) 432-1111: <input name='phone' length='50'/><br/>");
out.println("<input type='submit' name='action' value='store'/>");
out.println("</form>");
}
private void listEvents(PrintWriter out, SimpleDateFormat dateFormatter) {
result1 = session.createCriteria(Event.class).list();
if (result1.size() > 0) {
out.println("<h2>Event Info in database:</h2>");
out.println("<table border='1'>");
out.println("<tr>");
out.println("<th>Event title</th>");
out.println("<th>Event date</th>");
out.println("<th>Event id</th>");
out.println("</tr>");
for (Iterator it = result1.iterator(); it.hasNext();) {
Event event = (Event) it.next();
out.println("<tr>");
out.println("<td>" + event.getTitle()+ "</td>");
out.println("<td>" + dateFormatter.format(event.getDate()) + "</td>");
out.println("<td>" + event.getId() + "</td>");
out.println("</tr>");
}
out.println("</table>");
}//if
Servlet… list table of people
int num=0;
result2 = session.createCriteria(People.class).list();
if (result2.size() > 0) {
out.println("<h2>People Info in database:</h2>");
out.println("<table border='1'>");
out.println("<tr>");
out.println("<th>Person</th>");
out.println("<th>Phone</th>");
out.println("<th>Event coordinating</th>");
out.println("</tr>");
String unknown="unknown";
for (Iterator it = result2.iterator(); it.hasNext();) {
People person=(People)it.next();
out.println("<tr>");
out.println("<td>" + person.getName() + "</td>");
out.println("<td>" + person.getPhone() + "</td>");
out.println("<td>" + ((Event)result1.get(num)).getTitle() + "</td>");
num++;
out.println("</tr>");
}
out.println("</table>");
}
}
Create and store
protected void createAndStoreEvent(String name,String phone,String title, Date theDate) {
System.out.println("in create and store method");
Event theEvent = new Event();
People person=new People();
theEvent.setTitle(title);
theEvent.setDate(theDate);
person.setName(name);
person.setPhone(phone);
System.out.println("about to get current session and save event");
session.save(theEvent);
System.out.println("about to get current session and save person");
session.save(person);
System.out.println("done with saves");
}
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("in do get");
processRequest(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("in do post");
doGet(request, response);
}
}
events.People.java
public class People{
private String name;
private String phone;
private long id;
public People() {}
public long getId(){return id;}
public void setId(long id){this.id=id;}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
}
The primary key may be generated, native or
assigned. The strategy must be specified in the
hbm.xml. This is People.hbm.xml
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="events.People" table="people">
<id name="id" column="id">
<generator class="native"/>
</id>
<property name="name"/>
<property name="phone"/>
</class>
</hibernate-mapping>
Same hibernate.cfg.xml except
People table has been added.
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>

<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql://localhost/mydb</property>
<property name="connection.username">root</property>
<property name="connection.password"></property>

<property name="hibernate.connection.pool_size">10</property>

<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>


<property name="show_sql">true</property>
<property name="hbm2ddl.auto">update</property>
<property name="current_session_context_class">thread</property>
<mapping resource="events/Event.hbm.xml"/>
<mapping resource="events/People.hbm.xml"/>
</session-factory>
</hibernate-configuration>
ant build – still needs to be modified to build WEB-INF and
classes dirs, and copy files to there, then jar
<project name="hibernate-tutorial" default="compile">
<property name="sourcedir" value="${basedir}/src"/>
<property name="targetdir" value="${basedir}/bin"/>
<property name="librarydir" value="${basedir}/lib"/>
<path id="libraries">
<fileset dir="${librarydir}">
<include name="*.jar"/>
</fileset>
</path>
<target name="clean">
<delete dir="${targetdir}"/>
<mkdir dir="${targetdir}"/>
</target>
<target name="compile" depends="clean, copy-resources">
<javac srcdir="${sourcedir}"
destdir="${targetdir}"
classpathref="libraries"/>
</target>
<target name="copy-resources">
<copy todir="${targetdir}">
<fileset dir="${sourcedir}">
<exclude name="**/*.java"/>
</fileset>
</copy>
</target>
<target name="war" depends="compile">
<war destfile="HibernateApp2.war" webxml="web.xml">
<lib dir="${librarydir}">
</lib>
<classes dir="${targetdir}"/>
</war>
</target>
</project>
CRUD example
• The student table
Hibernate student info servlet
remarks
• Just one table marked
• Link above gives good information on how
to conduct queries.
• I used radiobuttons to indicate function
desired.
• I used the same ant/build and jar
commands as before.
• Same directory structure.
• Servlet in slide notes
Student.hbm.xml
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="data.Student" table="Students">
<id name="id" column="id">
<generator class="native"/>
</id>
<property name="name"/>
<property name="age"/>
<property name="gpa"/>
<property name="sex"/>
<property name="year"/>
</class>
</hibernate-mapping>
Some bits of the servlet
try {
// Begin unit of work
// HibernateUtil.getSessionFactory().getCurrentSession().beginTransaction();
sessionFactory = HibernateUtil.getSessionFactory();
session =sessionFactory.openSession();
session.beginTransaction();
if ("store".equals(request.getParameter("action"))) {
String name = request.getParameter("name");
String gpa = request.getParameter("gpa");
String year = request.getParameter("year");
String age = request.getParameter("age");
String sex = request.getParameter("sex");
if ("".equals(name) || "".equals(sex)||year.equals("")||gpa.equals("")||age.equals("")) {
out.println("<b><i>Please enter name, age, sex, gpa, year and sex.</i></b>");
} else {
System.out.println("before call to create and store");
createAndStoreEvent(name, age,year,sex,gpa);
out.println("<b><i>Added event.</i></b>");
}
}
else if ("list".equals(request.getParameter("action"))) {
// Print page
System.out.println("back in process ...about to call listevents");
listStudents(out);
}
Delete action
else if ("delete".equals(request.getParameter("action"))) {
String name = request.getParameter("name");
List marked=session.createQuery("from Student as
student where student.name=?").setString(0,name).list();
if(marked.size()>0){
Student student=(Student)marked.get(0);
out.println("deleting...."+ student.getName());
session.delete(student);
}
else {out.println("no match found");}
}else{//update
String name = request.getParameter("name");
String gpa = request.getParameter("gpa");
String year = request.getParameter("year");
String age = request.getParameter("age");
String sex = request.getParameter("sex");
List marked=session.createQuery("from Student as student where
student.name=?").setString(0,name).list();
if(marked.size()>0&&!"".equals(sex)&&!year.equals("")&&!gpa.equals("")&&!age.equal
s("")) {
Student student=(Student)marked.get(0);
student.setAge(Integer.parseInt(age));
student.setYear(year);
student.setGpa(Double.parseDouble(gpa));
student.setSex(sex);
session.update(student);
}
else {out.println("no match found");}
}
/*else a getinfo choice could look about the same
*/
I used radiobuttons
private void printStudentForm(PrintWriter out) {
out.println("<h2>Student info form:</h2>");
out.println("<form>");
out.println("Name: <input name='name' length='40'/><br/>");
out.println("Age: <input name='age' length='10'/><br/>");
out.println("Sex(Male/Female): <input name='sex' length='10'/><br/>");
out.println("Year: <input name='year' length='15'/><br/>");
out.println("GPA: <input name='gpa' length='10'/><br/>");
out.println("<input type='radio' name='action' value='list'> List<br>");
out.println(" <input type='radio' name='action' value='store' checked>
Store<br>");
out.println("<input type='radio' name='action' value='update'> Update<br>");
out.println(" <input type='radio' name='action' value='delete'> Delete<br>");
out.println("<input type='submit' />");
out.println("</form>");
}
List students
private void listStudents(PrintWriter out) {
result1 = session.createCriteria(Student.class).list();
if (result1.size() > 0) {
out.println("<h2>Student Info:</h2>");
out.println("<table border='1'>");
out.println("<tr>");
out.println("<th>Student name</th>");
out.println("<th>Student Age</th>");
out.println("<th>GPA</th>");
out.println("<th>Sex</th>");
out.println("<th>Year</th>");
out.println("</tr>");
for (Iterator it = result1.iterator(); it.hasNext();) {
Student student = (Student) it.next();
out.println("<tr>");
out.println("<td>" + student.getName()+ "</td>");
out.println("<td>" + student.getAge() + "</td>");
out.println("<td>" + student.getGpa() + "</td>");
out.println("<td>" + student.getSex() + "</td>");
out.println("<td>" + student.getYear() + "</td>");
out.println("</tr>");
}
out.println("</table>");
}//if
}
Hibernate configuration
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>

<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql://localhost/mydb</property>
<property name="connection.username">root</property>
<property name="connection.password"></property>

<property name="hibernate.connection.pool_size">10</property>

<property name="dialect">org.hibernate.dialect.MySQLDialect</property>

<property name="show_sql">true</property>
<property name="hbm2ddl.auto">update</property>
<mapping resource="Student.hbm.xml"/>
</session-factory>
</hibernate-configuration>
web-xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4"
xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<servlet>
<servlet-name>StudentInfo</servlet-name>
<servlet-class>data.StudentInfoServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>StudentInfo</servlet-name>
<url-pattern>/studentinfo</url-pattern>
</servlet-mapping>
</web-app>